850 THE SPINAL CORD. 



lumbar root (cat). 1 The lower limit cannot be so distinctly determined. 

 Transection below the sixth lumbar vertebra in the rabbit causes immediate 

 escape of urine from the bladder. 2 After spinal transection in the frog, rabbit, 

 cat, dog, and monkey, as after tantamount injuries in man, micturition is 

 interfered with. The exact share played in the suppression of function 

 of the organ by the interference with the innervation of its intrinsic mus- 

 culature and with that of other muscles, abdominal and perineal, accessory 

 to the emptying of the organ, is hardly known. In the first days after 

 the transection, the bladder can only be competently evacuated by artificial 

 means. This is easily effected, especially in the female, by pressure on 

 the distended viscus through the abdominal wall. The pressure should 

 be light, and quickly applied, and not maintained for long; it appears to 

 act by exciting a brief reflex micturition, no doubt of an imperfect character. 

 The tail is raised, the anus somewhat protruded, the knees are in the 

 bitch flexed, and a brief gush of urine is allowed to escape under the 

 pressure of the hand on the abdominal wall. The pressure alone is quite 

 inefficient to expel the urine, for it can be greater when first applied and 

 ineffective, than later when effective ; until the reflex ensues, the pressure 

 cannot void the bladder of its contents ; and although the pressure is main- 

 tained, the urine after the brief gush is not voided. It is then best to 

 desist from the abdominal compression for a minute or so, and reapply it 

 somewhat suddenly. Sometimes, instead of a brief gush, the whole contents 

 are allowed to be discharged. It has been shown 3 by comparing rate of 

 escape with intravesical pressure, that when the bladder is reflexly voided, in 

 response to stimulation of a sciatic nerve central to section, the reflex reaction 

 involves two acts, contraction of the detrusor and relaxation of the sphincter 

 (in addition to concomitant movements due to skeletal muscles). The im- 

 pression given to the hand when the bladder is emptied by pressure over the 

 hypogastrium is less that of contraction of the viscus than of a resistance low 

 down on the pelvic floor suddenly yielding. I have noted that, in the 

 monkey, variation of the level of the spinal transection anywhere between 

 sixth cervical and fourth lumbar appears to make no noticeable difference in 

 the degree of depression of the act of micturition, although in the latter case 

 the hypogastric afferent and efferent paths are intact, in the former not. This 

 depression seems as severe in the rabbit and cat as in the monkey. For many 

 days the urine may have to be evacuated either by inducing the reflex in the 

 above-mentioned way, or by the catheter. Later, the urine in the monkey as 

 well as in other laboratory animals comes to be voided " spontaneously " from 

 time to time. In some cases in the dog the urine even soon after transection 

 is voided in small quantities, very frequently and apparently without obvious 

 external stimulation having occurred, and without the bladder being even 

 moderately filled. Defaecation frequently accompanies the micturition; the 

 spinal micturition is followed by spinal wagging of the tail. 



Goltz and Ewald, 4 in their observations on dogs in which the lower region 

 of the spinal cord had been removed in toto, found the bladder empty itself 

 spontaneously from time to time months after removal of the cord ; but the 

 bladder had usually to be emptied by artificial means, and cystitis frequently 

 occurred. Though some degree of retention of urine is a common symptom 

 after total transverse lesion of the cord in man, and usually a permanent one, 

 I have never seen cystitis ensue after spinal transection in laboratory animals, 

 although the animals have been kept under observation many months. 



Defaecation. In the tortoise, after spinal transection behind the second of 

 the three roots of the sciatic plexus, defaecation occurs in the sense that faeces 



1 Colin C. Stewart, Am. Journ. PhysioL, Boston, 1899, vol. ii. p. 182. 



2 Masius, Bull. Acad. roy. d. sc. de Belg., Bruxelles, 1868. 



3 Alfons Haue, Arch.f. d. ges. PhysioL, Bonn, 1899, Bd. Ixxiii. S. 453. 



4 Ibid., 1896, Bd. Ixiii. S. 362. 



